Develop a system capable of reacting any of a number of drugs which are potentially useful in sickle cell anemia with HbS red cells and then return them to the circulation in a safe, simple, and highly controllable fashion. Develop a system suitable for a 70 kg adult which has the capability of reacting blood with a pharmacologic agent extracorporeally and returning the red cells to the patient. Unreacted drug returned to the circulation and hemolysis must be minimized and viability of the red cells as defined by isotonic survival studies must be determined. Study the conditions of the cellular hemaglobin-cyanate reaction.